1. Field of the Invention
This invention relates to an electron spin analyzer, particularly, to an electron spin analyzer which is preferably usable for a high effective electron spin analyzer such as an electronic material analyzer and a magnetic material surface analyzer.
2. Description of the Prior Art
A conventional electron spin analyzer tends to be enlarged for detecting scattered electrons effectively. For example, a Mott spin analyzer is required to detect scattered electrons over the wide scattered angle range of 95-145 degrees, and thus, the scattered electron detector thereof must be enlarged.
An enlargement of an apparatus is not desired in view of installment space and operationality, and thus, the electron spin analyzer is also being required to be downsized. However, if the conventional electron spin analyzer is downsized with maintaining the structure, it can detect the scattered electrons effectively.
It is an object of the present invention to provide an electron spin analyzer which can detect scattered electrons even if it is downsized.
For achieving the above object, this invention relates to a first electron spin analyzer comprising an electron beam-generating apparatus, a hemisphere accelerating electrode opposing to the electron beam-discharging hole of the electron beam-generating apparatus, an electrode supporter to support the accelerating electrode, a scattered electron detector provided on the outer surface of the accelerating electrode, and a scattering target provided on the electrode supporter inside the accelerating electrode,
the accelerating electrode having a double structure composed of an inner accelerating electrode with an inner introducing inlet and an outer accelerating electrode with an outer introducing inlet, the inner introducing inlet being larger than the outer introducing inlet.
Moreover, this invention relates to a second electron spin analyzer comprising an electron beam-generating apparatus, a hemisphere accelerating electrode opposing to the electron beam-discharging hole of the electron beam-generating apparatus, an electrode supporter to support the accelerating electrode, a scattered electron detector provided on the outer surface of the accelerating electrode, and a scattering target provided on the electrode supporter inside the accelerating electrode,
the accelerating electrode having a double structure composed of an inner accelerating electrode with an inner opening to introduce scattered electrons from the scattering target into the scattered electron detector and an outer accelerating electrode with an outer opening to do ditto, the inner opening being larger than the outer opening.
Furthermore, this invention relates to a third electron spin analyzer comprising an electron beam-generating apparatus, a hemisphere accelerating electrode opposing to the electron beam-discharging hole of the electron beam-generating apparatus, an electrode supporter to support the accelerating electrode, a scattered electron detector having a correcting electrode therein provided on the outer surface of the accelerating electrode, and a scattering target provided on the electrode supporter inside the accelerating electrode.
And then, this invention relates to a fourth electron spin analyzer comprising an electron beam-generating apparatus, a hemisphere accelerating electrode opposing to the electron beam-discharging hole of the electron beam-generating apparatus, an electrode supporter to support the accelerating electrode, a scattered electron detector provided on the outer surface of the accelerating electrode, and a scattering target provided on the electrode supporter inside the accelerating electrode, the scattered electron detector being arranged in the shifted direction from an introducing direction of electrons to be introduced by 100-140 degrees.
The inventors has intensely studied to prevent the degradation of the detection sensitivity of scattered electrons even if the electron spin analyzer is downsized. At last, they found the following fact: That is, the electron spin analyzer is so formed that its hemisphere accelerating electrode is composed of an inner accelerating electrode and an outer accelerating electrode, and its inner introducing inlet formed at the inner accelerating electrode has a larger size than that of its outer introducing inlet formed at the outer accelerating electrode, according to the first electron spin analyzer of the present invention. As a result, electron beams to be introduced can be converged onto a scattering target in high density, and thus, the convergence degree of the scattered electrons is increased.
According to the first electron spin analyzer of the present invention, the scattered electrons can be detected effectively, and the detection sensitivity can be increased.
Moreover, according to the second electron spin analyzer of the present invention, the inner opening formed at the inner accelerating electrode to introduce the scattered electrons into a scattered electron detector is larger than the outer opening formed at the outer accelerating electrode to do ditto. Therefore, the convergence degree of the scattered electrons is increased, so that the scattered electrons can be detected effectively at the scattered electron detector and the detection sensitivity of the analyzer can be increased.
Furthermore, according to the third electron spin analyzer of the present invention, since a correcting electrode to capture the scattered electrons for the scattered electron detector is provided, the convergence degree of the scattered electrons can be increased. Therefore, the detection sensitivity of the analyzer can be increased.
Then, the inventors have also figured out that, although the distribution of scattered electrons becomes maximum in the shifted direction from the introducing direction of the electron by 120 degrees in a normal size electron spin analyzer, it becomes maximum in the different direction from the shifted direction in a downsized electron spin analyzer. Since the fourth electron spin analyzer of the present invention is so fabricated that the scattered electron detector is positioned at the maximum distribution of the scattered electrons, the detection sensitivity of the scattered electrons can be increased.
The first through the fourth electron spin analyzers may be independently employed, respectively, but some of the analyzers may be combined in their respective characteristics. If all the analyzers are combined in their respective characteristics, the detection sensitivity of the scattered electrons can be extremely increased.